It is previously known to weave tubular weave in shaft frame machines which operate with a spool shuttle for drawing the draw-in thread through a shed formed with the warp threads. It is also previously known to weave flat-woven material which is removed from the machine and subsequently folded and pieced together at its free ends. The weave thus extends in the longitudinal direction of the warp threads and the tubular weave is established by piecing together the free ends of the warp threads. The joining has been carried out in the sewing department. The joining work takes place in a piecing area spread out in the longitudinal direction of the warp threads and it is known to distribute the exit positions of the warp thread ends in the piecing area so that a strong joint is obtained. With known equipment, the weaving of the flat-woven cloth is conducted in a weaving machine, which can be mounted in a weaving room. The joining or bringing-together of the warp thread ends is carried out in a sewing room, to which the woven material is transferred. In connection herewith, a stretching machine is used in known manner to heat-treat and stretch up the weave to allow the joining work. The joining work carried out in the sewing department has in itself partially been automated so that parts of the joining work could be carried out using a Jacquard machine. The known processes require however that the stretching machine function must be used on two separate occasions.
There is a need to increase the level of automation in tubular weave production while maintaining high strength in the turnover fold area. There is thus, for example, a desire for the whole or parts of the work in the sewing room to be eliminated, at the same time as the automated weave production enables the woven tubular weave to exhibit essentially the same strength around the whole circumference. The object of the invention is to solve, among other things, this problem.
The use of tubular weaving with a spool shuttle leads to quality problems, since the tensile stress in the weft threads cannot be kept even and appropriate, which means varying tensile effects upon the outer warp threads. The invention solves this problem by indicating a new path within the technique. Instead of carrying out the piecing function on the warp thread ends, this is carried out on the weft thread ends.
There is a definite wish for the new facilities to be implementable with tried and tested technique and not to require over-extensive conversion and design modification to the structures of existing shaft frame weaving machines. This problem too is solved by this invention.